Справочник Пользователя для Hynix 4GB PC3-12800 HMT351S6CFR8C-PB

Figure below represents the effective reference load of 25 ohms used in defining the relevant AC timing 

parameters of the device as well as output slew rate measurements.
It is not intended as a precise representation of any particular system environment or a depiction of the 

actual load presented by a production tester. System designers should use IBIS or other simulation tools to 
correlate the timing reference load to a system environment. Manufacturers correlate to their production 

test conditions, generally one or more coaxial transmission lines terminated at the tester electronics.

DQ

DQS

DQS

VDDQ

25 Ohm

VTT = VDDQ/2

CK, CK